With this mod cities can revolt from starvation and/or unhappiness in addition to and independent of cultural pressure.
When they do for a second time, they flip to Barbarian control.
The City Garrison promotion line helps decrease the revolt chance of a city.
For easier reference units now have their garrison value displayed in their tooltip.
Credit goes to the makers of the Planetfall mod, from where I blatantly stole this mechanic and turned it into a stand-alone component.
Enhanced City Revolts 29_11_2019
Cities can revolt from starvation and unhappiness, flip to barbarians with the second one